1. Field of The Invention
The present invention relates to archery bows for guiding arrows before and during the release of the arrow from the archery bow. In particular, the present invention relates to an adjustable plunger for balancing the side pressure from the arrow.
2. Description of The Prior Art
Archery bows and arrows have been in existence since the days of Robin Hood, however the technology of archery bows and arrows has changed considerably since then and through the years, new and improved archery bows and arrows have been introduced into the consumer market. Serious archers in today's consumer market use archery bows and arrows for hunting and sporting events and there is an ever increasing demand for a bow that will shoot arrows with a high degree of accuracy. To achieve this requires accessories that assist in maintaining the consistency of the trajectory of the arrow. One of the most important accessories is a plunger. Plungers are known in the prior art. The plunger is used to compensate for the horizontal oscillations generated in the arrow shaft during the release and acceleration of the arrow. There are many disadvantages associated with prior art plungers. The tension on the plunger and the pressure it generates is adjusted by spring tension. One disadvantage of prior art plungers is that they use set screws for adjusting the tension on the spring to loosen or tighten the tension on the plunger. After a period of time, the set screws become loosened because of the vibration caused by the archery bow when shooting an arrow or striking against an object. Another disadvantage is that arrows are generally made of two materials: aluminum and carbon. Aluminum arrows are generally thicker in diameter and heavier, and are used for indoor shooting. Carbon arrows are generally thinner in diameter and lighter, and are used for outdoor shooting. Therefore, two plungers are required, one for aluminum arrows and one for carbon arrows. The extra plungers are not cost efficient. Another disadvantage in prior art plungers is that the tuning process for adjusting the plunger requires at least four (4) to six (6) hours and is usually inaccurate because it is done by guesswork. When the plunger is damaged and must be replaced with a new one, previous plungers do not have means for reproducing the previously set position of the plunger. With the plunger not having a previous reference point, the time consuming task of readjusting the plunger is required for the archery bow to shoot correctly again.
The following prior art references are relevant to the field of the present invention.
1. U.S. Pat. No. 4,170,980 issued to Killian on Oct. 16, 1979 for "Archery Bow Arrow Rest" (hereafter "the Killian Patent").
2. U.S. Pat. No. 4,542,731 issued to Quartino on Sep. 24, 1985 for "Bow With Vertically And Horizontally Adjustable Arrow Support" (hereafter "the Quartino Patent").
3. U.S. Pat. No. 4,648,376 issued to Saunders on Mar. 10, 1987 for "Self Cleaning Pressure Button" (hereafter "the Saunders Patent").
4. U.S. Pat. No. 4,924,841 issued to Smith on May 15, 1990 for "Arrow Guide" (hereafter the Smith Patent").
5. U.S. Pat. No. 5,081,980 issued to Newbold on Jan. 21, 1992 for "Plunger Arrow Rest" (hereafter "the Newbold Patent").
The Killian Patent discloses an arrow rest for an archery bow. The cylinder is threaded externally and the bore through the bow handle is threaded to provide a connection of the cylinder to the handle. A lock nut is threaded onto the outer projecting end of the cylinder to abut the outer surface of the handle and lock the cylinder securely in place. A locking screw is also provided in the threaded bore of the cylinder to abut the adjustment screw and retain the cylinder in the desired position of adjustment. The arrow rest arm is mounted pivotally on the support plate by the pivot pin for arcuate movement of the arm in opposite directions.
The Quartino Patent discloses a bow with vertical and horizontal adjustable arrow support. There is a vertical aperture extending through the bow handle section from the arrow side to the opposite side. A cylindrical support extends through the vertical aperture which is slidable in a vertical direction and when tightened, fixes the support member in a vertically adjusted position. The support member entering from the side opposite to the arrow side is a hollow cylinder and carries the inner end portion of an arrow spacing plunger. A jamb nut engaged on the hollow cylinder is tightened against the end of support member, and thereby locks the horizontal adjustment of the arrow spacing plunger.
The Saunders Patent discloses a self cleaning pressure button. It includes a housing adapted to extend through an opening in a bow handle which has a chamber. The chamber extends to an opening on one end. A plunger is slidably disposed within the chamber, and the plunger has one end extending through the opening and forming a small space between the one end of the plunger and the housing. A spring is provided within the plunger for biasing the plunger in a direction toward the arrow. An opening is provided for permitting air to enter the chamber, and a pump is disposed within the chamber for causing air to be forced out through the space between the housing and the plunger when the plunger operates as a shock absorber. A filter is provided in the chamber to prevent dirt from entering the chamber.
The Smith Patent discloses an arrow guide. It includes a hinge base, an arrow rest lever rod and a hollow threaded fastener which are removably affixed thereon. The hinge base is mounted onto the exterior surface of the bow in the area of the bow riser. The hinge base is retained in position on the bow by the hollow threaded fastener, which in turn is maintained in position by a lock nut. The arrow rest lever rod self-positions laterally in an approximate forty-five degree angle relative to the hinge base. A plunger disposed within the hollow threaded fastener is biased by a compression spring which is secured within the hollow threaded fastener by an adjustment screw. The adjustment screw is adapted to be threaded into the distal end of the hollow threaded fastener, thereby preventing the removal of the spring and the plunger.
The Newbold Patent discloses a plunger arrow rest. It includes a cushion plunger assembly and an arrow support. The cushion plunger assembly includes an elongated plunger, and is mounted to an archery bow to engage the side of an arrow with the plunger. A plunger bore extends longitudinally and concentrically into the plunger. The arrow support is a one piece metal wire extending through the mounting holes. The arrow support wire extends outward from the mounting hole at an elevation that is generally below the plunger to form a support arm.
None of the prior art patents are designed with a measuring device. In tensioning the plunger, the prior art patents employ a "try-and-adjust-after-error" technique which takes a considerable amount of time.
Therefore, there is a need for an improved plunger that will have precise measurements to facilitate the tuning process. It is desirable to design a plunger wherein the problem of set screws in prior art devices is eliminated. It is also desirable to have a universal plunger which can be utilized with both aluminum arrows and carbon arrows.